Determinación del caudal ecológico en el río Ilave, con la metodología IFIM-PHABSIM

Dany Alexander Aguilar Mamani; Jose Antonio Vargas Maron; Omar Neira; Felipe Condori; Howard Rivera; Gloria Arazola Mamani · Revista Ciencia Agraria (2026) · DOI: 10.35622/j.rca.2026.02.002

Resumen

Ecological flow is the minimum amount of water required in a river to preserve the biota in that environment. The aim of this study was to determine the ecological flow of the Ilave River (in the Churo sector, El Collao Province, Puno, Peru) using the Instream Flow Incremental Methodology (IFIM) and hydrobiological simulation with the open-source software PHABSIM, considering rainbow trout (Oncorhynchus mykiss) as the indicator species. Historical records of mean monthly flows for the period 2000–2025 were analyzed, complemented by field measurements of water velocity, depth, temperature, and channel index. The results indicate that the optimal ecological flow for trout survival is 3 m³/s, with suitable temperature conditions ranging from 0 to 18 °C, a minimum depth of 0.2 m, and a channel index from 1 to 8. Statistical analysis showed that, in 11 months over the last twenty-six years, flows were below 3 m³/s, reflecting a progressive deterioration of the aquatic habitat for the fish under study. In conclusion, these findings show that the reduction in flow, mainly due to anthropogenic activities, compromises the hydrobiological sustainability of the Ilave River and endangers the persistence of its native and exotic biota. The implementation of integrated water resource management policies aimed at conserving the natural flow regime of the Ilave River is recommended.

Instituciones: Universidad Nacional del Altiplano